Amphibious platform vehicle-vessel

ABSTRACT

An amphibious platform vehicle-vessel to support and to move hydraulically operated and controlled earth-moving and lifting equipment, such as excavators and cranes, on solid ground, semi-solid or marshy ground, shallow water, and deeper water. The modular units can be transported to a worksite on separate trailers and assembled and reconfigured on site. Two compartmented pontoon units are mounted to an adaptive cross member that can accommodate different types of moving-lifting equipment through different mounting flanges, and to auxiliary cross members. Propulsion is provided through amphibious cleats on drive chains in chain tracks driven by dual-motor driving drums and over a tension-adjusting passive chain roller, surrounding a sealed pontoon shell internally reinforced with bulkhead partitions, beam shell-bottom stiffeners, and pressed-angle shell-bottom stiffeners. An extendable auxiliary float can be extended outward from each compartmented pontoon for increased stability in floating operations. Spud units having a chain-drive spud and a spud-driving mount unit with spud-mount wear strips are hydraulically raised and lowered by a spud-driver motor at the command of the equipment operator using a spud-control switch.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of pending application Serial No.U.S. Ser. No. 16/678,248, filed on Nov. 8, 2019, the full disclosure ofwhich is incorporated by reference herein and priority of which ishereby claimed.

BACKGROUND OF THE INVENTION

This invention provides an amphibious platform vehicle-vessel to supportand to move hydraulically operated and controlled earth-moving andlifting equipment, such as excavators and cranes, on solid ground,semi-solid or marshy ground, shallow water, and deeper water.

Amphibious vehicles, known as marsh buggies, were first developed tosupport oil and gas exploration operations conducted in marshy or swampyterrain. Marsh buggies typically include a pair of pontoons connected toa center platform. The pontoons are usually surrounded by a cleatedtrack system which is capable of engaging ground, water, or swamp landto propel the vehicle. The track system uses one or more endless chainssurrounding the periphery of each pontoon. The endless chains,supporting the cleated tracks, are driven about the periphery of thepontoons, by a sprocket or other means, in order to provide propulsionto the vehicle. By varying the track speed around each pontoon, thevehicle can be advanced, turned, or reversed. Marsh buggies are idealfor operation in wetlands, marshlands, and other low-lying areas becauseof the relatively low pressures exerted on the ground through the large,tracked pontoons. Therefore, marsh buggies will not sink into the softsoil in low-lying or submerged areas and have minimal environmentalimpact while traveling to and from a remote job site. Marsh buggies havebeen adapted to haul personnel and cargo as well as serve as theoperating platform for various types of equipment, such as excavators,draglines, and backhoes.

Marsh buggies are used to support heavy earth-moving equipment inlow-lying, soft terrain areas for operations such as wetlandrestoration, crust management (dewatering), dredging, levee building,coastal erosion, and other environmental remediation operations.

Marsh buggies have proved useful in performing earth moving operationsin soft-terrain and are often capable of floating in order to navigatesmall bodies of water. Although marsh buggies are often capable ofmoving through any terrain, these vehicles aren't designed to operatewhile floating in water deeper than their pontoons. Thus, marsh buggiesare limited in performing earth-moving operations to dry land orrelatively shallow water where their pontoons are resting on the ground.In deeper water, the pushing and pulling forces exerted by theexcavation equipment will instead push or pull the marsh buggy itselfacross the surface of the water.

Marsh buggies can support earth-moving operations in somewhat deeperwater through the use of spuds, which are a form of pilings that can beextended downward to rest on or in the ground under the water.Deployment of such spuds can fix the marsh buggy in place against thepushing and pulling forces of the excavation operations. Presently,deployment and retracting of the spuds can be a cumbersome process,especially under circumstances where spuds become stuck in muddy ground.The use of spuds significantly slows down the ability to advanceoperations across a large area. Spuds are effective for preventingmovement across the water surface but are less effective in stabilizingagainst rocking motion caused either by swelling of the water surface orby operation of the excavation equipment.

Different moving-lifting equipment, while being similar in beinghydraulically operated, requires different mounting hardware, makingchanging from one piece of equipment to another a complex endeavor thatis difficult to accomplish at a remote worksite.

Marsh buggies are able to propel themselves and their attached equipmentaround a worksite, but must first be transported to the worksite, whichis usually remotely located. Such transport often involves some use ofpublic roads and highways, which impose limitations of size and weight,which in turn might require partial disassembly of large heavy equipmentand then reassembly at a remote and inconvenient worksite

What is needed is an amphibious platform vehicle-vessel providinghydraulically powered operation of spuds by the equipment operatorthrough a control inside the cab, providing better stability in deeperwater, providing a modular structure allowing transport as modularsections and allowing on-site assembly and on-site mounting to differentmoving-lifting equipment, and providing other improvements andefficiencies.

SUMMARY OF THE INVENTION

This invention provides an amphibious platform vehicle-vessel to supportand to move hydraulically operated and controlled earth-moving andlifting equipment, such as excavators and cranes, on solid ground,semi-solid or marshy ground, shallow water, and deeper water. Themodular units can be transported to a worksite on separate trailers andassembled and reconfigured on site. Two compartmented pontoon units aremounted to an adaptive cross member which can accommodate differenttypes of moving-lifting equipment through different mounting flanges,and to auxiliary cross members. Propulsion is provided throughamphibious cleats on drive chains in chain tracks driven by dual-motordriving drums and over a tension-adjusting passive chain roller,surrounding a sealed pontoon shell internally reinforced with bulkheadpartitions, beam shell-bottom stiffeners, and pressed-angle shell-bottomstiffeners. An extendable auxiliary float can be extended outward fromeach compartmented pontoon for increased stability in floatingoperations. Spud units having a chain-drive spud and a spud-drivingmount unit with spud-mount wear strips are hydraulically raised andlowered by a spud-driver motor at the command of the equipment operatorusing a spud-control switch.

BRIEF DESCRIPTION OF THE DRAWINGS

Reference will now be made to the drawings, wherein like parts aredesignated by like numerals, and wherein:

FIG. 1 is a perspective view of the amphibious platform vehicle-vesselof the invention, in use, with spud units extended downward andextendable auxiliary floats extended outward;

FIG. 2 is a perspective view of the amphibious platform vehicle-vesselof the invention, in use, with spud units retracted upward andextendable auxiliary floats retracted inward;

FIG. 3 is a detail view of the spud unit of the amphibious platformvehicle-vessel of the invention;

FIG. 4 is an exploded view of the amphibious platform vehicle-vessel ofthe invention;

FIG. 5 is a plan view of the amphibious platform vehicle-vessel of theinvention with the moving-lifting equipment installed;

FIG. 6 is a plan view of the amphibious platform vehicle-vessel of theinvention with the moving-lifting equipment not installed;

FIG. 7 is a perspective cutaway view of the amphibious platformvehicle-vessel of the invention;

FIG. 8 is a side cutaway view of the amphibious platform vehicle-vesselof the invention;

FIG. 9 is a section view of the sealed pontoon shell of the amphibiousplatform vehicle-vessel of the invention;

FIG. 10 is a perspective section view of the sealed pontoon shell of theamphibious platform vehicle-vessel of the invention;

FIG. 11 is a detail view of the chain tracks of the amphibious platformvehicle-vessel of the invention;

FIG. 12 is a detail view of the dual-motor driving drums of theamphibious platform vehicle-vessel of the invention; and

FIG. 13 is a detail view of the tension-adjusting passive chain rollerof the amphibious platform vehicle-vessel of the invention.

DETAILED DESCRIPTION OF THE INVENTION

Referring to FIG. 1 and FIG. 2, the amphibious platform vehicle-vessel10 provides for the use of moving-lifting equipment 60 on solid ground,semi-solid or marshy ground, shallow water, and deeper water. Themoving-lifting equipment 60 can be of an excavator or backhoe type, asillustrated, or of a crane type. The different types and brands ofmoving-lifting equipment have different physical mountingconfigurations, and the amphibious platform vehicle-vessel 10 isadaptable to different equipment, as treated below. The amphibiousplatform vehicle-vessel 10 is modular and can be transported to or froma worksite as separate modules of size and weight appropriate to fitonto a truck trailer operating on existing roads and highways. Theamphibious platform vehicle-vessel 10 provides for movement of mountedmoving-lifting equipment 60 around a worksite, including movementbetween solid, marshy, and water surfaces.

The moving-lifting equipment 60 is hydraulically operated and has anequipment hydraulic controller 61 having a number of channels, and anequipment operator control 62, often in the form of a joystick inside anoperator's cab, through which the equipment operator controls thehydraulic pressure directed by the equipment hydraulic controller 61 tothe various parts of the moving-lifting equipment 60. The amphibiousplatform vehicle-vessel 10 provides an additional spud-control switch 45allowing powered deploying and retracting of spuds, as treated below.

The amphibious platform vehicle-vessel 10 provides two compartmentedpontoons 20, each having a sealed pontoon shell 21, which are mounted toan adaptive cross member 32 and to two auxiliary cross members 34, alltogether forming a platform for the moving-lifting equipment 60. In theillustrated embodiment, an excavator is mounted to the adaptive crossmember 32 through an excavator-equipment mounting flange 35.

Each compartmented pontoon 20 provides an extendable auxiliary float 50which can be retracted into the pontoon when not needed or when beingtransported, and can be extended out from the pontoon when needed insufficiently deep water to float the amphibious platform vehicle-vessel10, where the extended extendable auxiliary float 50 will stabilizeagainst rocking motion and will provide better counteracting leverageagainst the forces resulting from use and movement of the moving-liftingequipment 60. The sealed pontoon shell 21 remains sealed and airtighteven when the extendable auxiliary float 50 is extended.

One or more spud units 40 are provided, which can be deployed downwardpast the bottom of the pontoons to contact or to partially penetrate theground surface such as a marshy ground surface or the bed surfaceunderneath water. The deployed spuds provide anchoring and stability tocompensate for the stability lost when the bottom surface of the pontoonfloats away from solid contact with the ground. The spud units 40 can beretracted upward above the bottom of the pontoons when not needed. Theamphibious platform vehicle-vessel 10 provides for deployment andretracting of the spud units 40 via the spud-control switch 45, by theoperator from the cab of the moving-lifting equipment.

The amphibious platform vehicle-vessel 10 provides for movement acrossthe ground, marsh, or water surface by providing drive chains 23, inloops, traveling in chain tracks 22, having attached amphibious cleats24, driven by a dual-motor driving drum 25, with proper tension upon theloops of drive chains set and maintained through the tension-adjustingpassive chain roller 26, as treated below.

In use, as illustrated, each compartmented pontoon 20 has anelongated-axial form along a forward-rearward line of travel. Eachsealed pontoon shell 21 has top and side surfaces and a bottom surfacealong the elongated axis. When the two compartmented pontoons 20 aremounted to the adaptive cross member 32 and auxiliary cross members 34,each compartmented pontoon 20 has a nominal inward and outward side.

Referring to FIG. 3, the spud unit 40 provides a chain-drive spud 41mounted upon the compartmented pontoon 20 by a spud-driving mount unit42 that also drives the chain-drive spud 41 up and down in use.Spud-mount wear strips 43 are arrayed on the surfaces of thespud-driving mount unit 42 which are in sliding contact with thechain-drive spud 41. The spud-mount wear strips 43 provide surfaceswhich can be worn down with use and can be replaced easily as needed.The spud-mount wear strips 43 should be made of a material which willnot abrade or wear the chain-drive spud 41, but instead will be abradedor worn. The spud-mount wear strips 43 should provide a low-frictionsurface resistant to the wet, dirty, and sometimes salty conditions ofuse. A spud-driver motor 44 provides the motive force for thespud-driving mount unit 42 to drive the chain-drive spud 41 up and downas needed and as controlled by the spud-control switch 45 treated below.

Referring to FIG. 4, the spud-control switch 45 is added to theequipment operator control 62, usually in the cab of the moving-liftingequipment 60, and controls a channel of the equipment hydrauliccontroller 61 to exert hydraulic pressure through a pair of hydrauliclines, either differentially or uniformly, upon the spud-driver motor44, which will move the chain-drive spud 41 either up or down, or holdthe chain-drive spud 41 in place, depending upon the relative pressuresin the two hydraulic lines. In this way, the spud-control switch 45provides control of the deployment and retracting of the spuds to theequipment operator from the operator's normal location inside the cab,and without leaving the other equipment controls untended.

Referring still to FIG. 4, the amphibious platform vehicle-vessel 10 ismodular, and can be taken apart for transport, with each modularcompartmented pontoon 20 being of a size and shape allowing each to betransported on a truck's trailer over public roads and highways. Becausethe extendable auxiliary float 50 can be retracted to be substantiallyflush with the sealed pontoon shell 21, it does not widen thecompartmented pontoon 20 module during transport or storage. Aftertransport to a usually remote worksite, the amphibious platformvehicle-vessel 10 can be assembled and moving-lifting equipment 60attached on-site. The amphibious platform vehicle-vessel 10 canaccommodate various types of moving-lifting equipment 60, such asexcavators, backhoes, cranes, gantries, concrete pumps, or specializedequipment for moving earth or for moving objects. This accommodation isachieved through the use of different mounting flanges, such as theexcavator-equipment mounting flange 35 and the crane-equipment mountingflange 36 illustrated. The mounting flanges differ in their exactdiameters and number, arrangement, and threading of holes. The adaptivecross member 32 provides a variety of holes of sizes and patterns toaccommodate the different mounting flanges. With the appropriateexcavator-equipment mounting flanges 35, 36 different moving-liftingequipment 60 can be mounted, unmounted, and remounted on the amphibiousplatform vehicle-vessel 10 at or near the worksite.

Referring to FIG. 5 and FIG. 6, the extendable auxiliary floats 50 canbe extended outward from the compartmented pontoons 20 as needed inwater deep enough to float the amphibious platform vehicle-vessel 10 andcan be retracted into the compartmented pontoons 20 when not needed andduring transport and storage. The extendable auxiliary floats 50, whenextended, significantly extend the floating area outwards, whichsignificantly stabilizes the provided platform against the forcesexerted by the moving-lifting equipment 60 in operation.

Increased structural stability in all operating conditions is providedby the auxiliary cross members 34 located fore and aft of the adaptivecross member 32. The auxiliary cross members 34 accommodate portions ofthe beams of the extendable auxiliary floats 50 when retracted, andconnect the beams to each other when extended, transferring forcebetween the extendable auxiliary floats 50 without placing much twistingor deforming force on or through the sealed pontoon shells 21.

The compartmented pontoons 20 each provide an adaptive-cross-membermount 31 and auxiliary-cross-member mounts 33 for connection, in use, tothe adaptive cross member 32 and auxiliary cross members 34.

Referring to FIG. 7 and FIG. 8, each compartmented pontoon 20 furtherprovides bulkhead partitions 27 which form separate sealed, airtightcompartments inside the sealed pontoon shell 21. The extendableauxiliary float 50, when retracted, also serves as a separate sealedairtight compartment inside the boundaries of the sealed pontoon shell21. The bulkhead partitions 27 also serve as structural bracing for thesealed pontoon shell 21. Additional support and bracing for the bottomsurface of the sealed pontoon shell 21 is provided by beam shell-bottomstiffeners 28 and pressed-angle shell-bottom stiffeners 29 asillustrated, and as treated below.

Referring to FIG. 9, along the elongated, forward-rearward axis of thebottom surface of the sealed pontoon shell 21, the bottom surface, andthe chain tracks 22 along the bottom surface, have a flat profile alonga central portion, rounded profiles along each end portion, and aslightly angled profile along the portions intermediate between centerand ends. The slight angle along the intermediate portions can beapproximately one or two degrees. In use, not in motion, on a solidground surface, the flat central portion, directly underneath themoving-lifting equipment 60, provides support and stability. In motion,the rounded profiles along each end portion allow for approaching andclimbing inclined surfaces, and the slightly angled intermediateprofiles allow for a more gradual approach of the amphibious cleats 24to the ground surface, when on solid or marshy ground, thereforeapplying shearing force more gradually, and at initially shallowerdepth, than with a longer section of flat bottom surface.

Referring additionally to FIG. 10, the bottom surface of the sealedpontoon shell 21 is subject to straining force and is reinforced by beamshell-bottom stiffeners 28 and pressed-angle shell-bottom stiffeners 29.The beam shell-bottom stiffeners 28, such as sections of steel I-beam,are heavier and stronger, and are used along the central portion of thebottom surface. The pressed-angle shell-bottom stiffeners 29, such assteel bar bent on a press brake, are lighter and less expensive than thebeams. Another consequence of the provided slightly angled profile ofthe intermediate portions of the bottom surface is a reduced amount ofstraining force placed upon those intermediate portions in use.Therefore, the lighter and less expensive pressed-angle shell-bottomstiffeners 29 are provided in those intermediate portions, providingsufficient reinforcement while reducing weight and expense. Thepressed-angle shell-bottom stiffeners 29 are also used in therounded-profile end portions, for the same reasons. The reduced overallweight of the compartmented pontoon 20 reduces the contact pressure withthe ground, improving operating efficiency and reducing wear.

Referring to FIG. 11, the compartmented pontoon 20 of the amphibiousplatform vehicle-vessel 10 provides chain tracks 22 mounted upon theouter top and bottom surfaces of the sealed pontoon shell 21. The chaintracks 22 provide a protective shield and guide for the drive chains 23while protecting the airtight surface of the sealed pontoon shell 21.Each of the chain tracks 22 provides two vertical pieces such as A-36steel bar material which are fillet welded onto the sealed pontoon shell21, on the outside of the pieces, as illustrated, leaving a gap orchannel for the placement of an appropriate horizontal piece such as abar of HARDOX 400 steel bar, which is fillet welded to the inner sidesof the vertical pieces as illustrated. Worn or otherwise damagedportions of the chain tracks 22 can be repaired or replaced as needed.

Referring to FIG. 12, a dual-motor driving drum 25 is provided for eachcompartmented pontoon 20. Provision of a driving drum eliminates the useof an intermediate driving chain to drive the sprockets to drive thedrive chains 23, simplifying operation and improving the handling andbraking capabilities of the motor unit. Each dual-motor driving drum 25,and therefore each compartmented pontoon 20, has two hydraulic motors,providing the whole amphibious platform vehicle-vessel 10 with fourmotors. The normal operation of such paired hydraulic motors, whensupplied from a shared pair of hydraulic lines, is to compensate for andbalance each other while moving in either direction or while being heldstatic in a braking condition.

Referring to FIG. 13, a tension-adjusting passive chain roller 26 isprovided for each compartmented pontoon 20. The tension-adjustingpassive chain roller 26 maintains a substantially constant tension uponthe drive chains 23 to keep them within the chain tracks 22 and keepthem engaged with the sprockets of the dual-motor driving drum 25.Larger and general adjustment can be made manually after repair ormodification to the drive chains 23 or to adjust for extreme temperatureor environmental changes, and smaller moment-to-moment adjustmentsduring operations are made automatically.

Many other changes and modifications can be made in the system andmethod of the present invention without departing from the spiritthereof. We therefore pray that our rights to the present invention belimited only by the scope of the appended claims.

We claim:
 1. An amphibious platform vehicle to support moving-liftingequipment, comprising: (i) a pair of buoyant flotation pontoons, eachpontoon having a sealed pontoon shell formed with an outer wall and aninner wall, each outer wall defining a sealed compartment; (ii) anauxiliary float fitted into the sealed compartment of each of theflotation pontoons, the auxiliary float being extendable from andretractable into a respective sealed compartment upon demand; and (iii)an actuator unit for moving the auxiliary float in and out of the sealedcompartment.
 2. The apparatus of claim 1, comprising an adaptive crossmember mounted between the pair of flotation pontoons adapted forinstallation of moving-lifting equipment and routing of hydraulic linesand an excavator-equipment mounting flange adapted for installation ofexcavator-type moving-lifting equipment onto said adaptive cross member.3. The apparatus of claim 2, comprising a pair of adaptive cross membermounts being carried by the inner wall of a respective flotation pontoonand being adapted for connection to the adaptive cross member.
 4. Theapparatus of claim 2, comprising a pair of spaced-apart auxiliary crossmembers extending between the flotation pontoons in a transverserelationship to longitudinal axes of the flotation pontoons and a pairof auxiliary cross member mounts carried by the inner walls of theflotation pontoons, each auxiliary cross member mount being engageablewith a respective auxiliary cross member.
 5. The apparatus of claim 2,comprising a crane-equipment mounting flange adapted for installation ofcrane-type moving-lifting equipment onto said adaptive cross member. 6.The apparatus of claim 1, comprising endless track drive chains mountedon each of the flotation pontoons for movement within chain tracks andamphibious cleats carried by the track drive chains for providingpropulsion to the amphibious platform vehicle on land and in water. 7.The apparatus of claim 6, comprising a dual-motor driving drum mountedupon said sealed pontoon shell, having sprockets engaging with saiddrive chains, adapted to drive said drive chains along said chaintracks, thereby moving said amphibious cleats in propulsive relation tothe ground surface and a tension-adjusting passive chain roller mountedupon said sealed pontoon shell, adapted to provide adjustable tensionupon the loops of said drive chains.
 8. The apparatus of claim 1,comprising a crane-equipment mounting flange adapted for installation ofcrane-type moving-lifting equipment onto said adaptive cross member. 9.The apparatus of claim 1, comprising a pair of spud units, each mountedoutboard of the outer wall of a respective flotation pontoon, the spudunits being adapted to provide anchoring and stability when positioneddownward onto or into the ground surface, and to avoid interference withmovement when positioned upward above the ground surface.
 10. Theapparatus of claim 9, wherein each spud unit comprises an elongatedchain-drive spud member adapted to be moved downward and upward upondemand, a spud mount-and-drive unit adapted to mount said spud member atan outward side of a respective pontoon and to drive said spud memberupward and downward, a plurality of spud-mount wear strips arrayed uponsaid spud mount-and-drive unit at the points of contact with said spudmember, adapted to facilitate the smooth movement of said spud memberwithin said spud mount-and-drive unit and to provide repairable andreplaceable wear surfaces; and a spud-driver motor adapted to providemotive force for said spud mount-and-drive unit to drive said spudmember upward and downward.
 11. The apparatus of claim 1, comprising aplurality of bulkhead partitions arrayed inside said floatation pontoonsto provide structural support and to form separate airtight chamberswithin said floatation pontoon.
 12. A method, comprising the steps of:(i) providing an amphibious vehicle supporting moving-lifting equipment,the vehicle comprising: (a) a pair of buoyant flotation pontoons, eachpontoon having a sealed pontoon shell formed with an outer wall and aninner wall, each outer wall defining a sealed compartment; (b) anauxiliary float fitted into the sealed compartment of each of theflotation pontoons, the auxiliary float being extendable from andretractable into a respective sealed compartment upon demand; (c) a pairof elongated spuds, each mounted at an outward side of a respectivepontoon; and (d) propulsion tracks mounted on each of the pontoons forproviding propulsion of the vehicle on land and in water; (ii)positioning the vehicle at a worksite; (iii) extending the auxiliaryfloats from the pontoons and providing increased stability to thevehicle; and (iv) embedding the spuds into the ground, thereby furtherstabilizing the vehicle at the worksite.
 13. The method of claim 12,comprising the steps of performing moving-lifting operations, retractingthe spuds above the propulsion tracks, retracting the auxiliary floatsinto the pontoons, and moving the vehicle to another location.
 14. Themethod of claim 12, wherein the vehicle comprises an adaptive crossmember mounted between the pair of flotation pontoons adapted forinstallation of moving-lifting equipment and routing of hydraulic lines,an excavator-equipment mounting flange adapted for installation ofexcavator-type moving-lifting equipment onto said adaptive cross member,a pair of adaptive cross member mounts being carried by the inner wallof a respective flotation pontoon and being adapted for connection tothe adaptive cross member, a pair of spaced-apart auxiliary crossmembers extending between the flotation pontoons in a transverserelationship to longitudinal axes of the flotation pontoons, and a pairof auxiliary cross member mounts carried by the inner walls of theflotation pontoons, each auxiliary cross member mount being engageablewith a respective auxiliary cross member.
 15. The method of claim 14,wherein the vehicle comprises a crane-equipment mounting flange adaptedfor installation of crane-type moving-lifting equipment onto saidadaptive cross member.
 16. The method of claim 12, wherein thepropulsion tracks comprise endless track drive chains mounted on each ofthe flotation pontoons for movement within chain tracks and amphibiouscleats carried by the track drive chains for providing propulsion to theamphibious platform vehicle on land and in water.
 17. The method ofclaim 16, wherein the vehicle comprises a dual-motor driving drummounted upon said sealed pontoon shell, having sprockets engaging withsaid drive chains, adapted to drive said drive chains along said chaintracks, thereby moving said amphibious cleats in propulsive relation tothe ground surface and a tension-adjusting passive chain roller mountedupon said sealed pontoon shell, adapted to provide adjustable tensionupon the loops of said drive chains.
 18. The method of claim 12, whereinthe vehicle comprises a crane-equipment mounting flange adapted forinstallation of crane-type moving-lifting equipment onto said adaptivecross member.
 19. The method of claim 12, wherein each spud unitcomprises an elongated chain-drive spud member adapted to be moveddownward and upward upon demand, a spud mount-and-drive unit adapted tomount said spud member at an outward side of a respective pontoon and todrive said spud member upward and downward, a plurality of spud-mountwear strips arrayed upon said spud mount-and-drive unit at the points ofcontact with said spud member, adapted to facilitate the smooth movementof said spud member within said spud mount-and-drive unit and to providerepairable and replaceable wear surfaces; and a spud-driver motoradapted to provide motive force for said spud mount-and-drive unit todrive said spud member upward and downward.
 20. The method of claim 12,wherein the vehicle comprises a plurality of bulkhead partitions arrayedinside said pontoons to provide structural support and to form separateairtight chambers within said pontoon.